The goals of the proposed project are 1) to train the applicant to conduct independent, novel, biomedical research as academic faculty at a vetinary or mdecal school and 2) to investigate molecular interactions between the non-polymorphic MHC class I-like human CDld molecules and potential ligands. This award will allow the applicant to use her molecular biology experience during an intensitive period of research in the sponsor's laboratory, in which the applicant to use her molecular biology experience during an intensive period of research in the sponsor's laboratory, in which the applicant will gain experience in the related fields of protein biochemistry and cellular immunology while continuing her education in immunology. Despite reports describing cell-mediated immune responses restricted to human CD1a, -b, and -c molecules and mouse CD1, no clear evidence of human CD ld involvement in immune responses has been reported. The proposed research is designed to determine if human CDld molecules can function in an antigen presenting capacity, and their possible role in immunity. Specifically, the candidate will work with Dr. Kroneberg to determine the types of ligand(s) that associate with human CDld and their affinities of binding. We propose to determine whether human CDld can bind lipids or glycolipids, similar to the other molecule members of the human CD1 family, or peptides, as does its murine homologue. The biological relevance of human CD1d ligand binding will be addressed by deriving CDld/antigen specific T cells from human peripheral blood, similar to studies performed in the mouse in the laboratory of the sponsor. Specifically, we propose to detemrine if CDld-restircted T cell are autoreactive, as has been reported for a conserved subset of T cells in the mouse or if cell-mediated immune responses require a human CD1d-associated ligan. In addition, the applicant will determine if ligan-binding to human CDld or T cell recognition requires b2-microglobulin with the CDld heavy chain. The development of human CDld-specific expression constructs, transfected cell lines, and purified protein will facilitate these studies.